Pre-Flight Testing and Performance of a Ka-Band Software Defined Radio

National Aeronautics and Space Administration (NASA) has developed a space-qualified, reprogrammable, Ka-band Software Defined Radio (SDR) to be utilized as part of an on-orbit, reconfigurable testbed. The testbed will operate on the truss of the International Space Station beginning in late 2012. Three unique SDRs comprise the testbed, and each radio is compliant to the Space Telecommunications Radio System (STRS) Architecture Standard. The testbed provides NASA, industry, other Government agencies, and academic partners the opportunity to develop communications, navigation, and networking applications in the laboratory and space environment, while at the same time advancing SDR technology, reducing risk, and enabling future mission capability. Designed and built by Harris Corporation, the Ka-band SDR is NASA's first space-qualified Ka-band SDR transceiver. The Harris SDR will also mark the first NASA user of the Ka-band capabilities of the Tracking Data and Relay Satellite System (TDRSS) for on-orbit operations. This paper describes the testbed's Ka-band System, including the SDR, travelling wave tube amplifier (TWTA), and antenna system. The reconfigurable aspects of the system enabled by SDR technology are discussed and the Ka-band system performance is presented as measured during extensive pre-flight testing

Wideband and Narrowband Spectrum Sensing Methods Using Software Defined Radios

The ability to accurately sense the surrounding wireless spectrum, without having any prior information about the type of signals present, is an important aspect for dynamic spectrum access and cognitive radio. Energy detection is one viable method, however its performance is limited at low SNR and must adhere to Nyquist sampling theorem. Compressive sensing has emerged as a potential method to recover wideband signals using sub-Nyquist sampling rates, under the presumption that the signals are sparse in a certain domain. In this study, the performance and some of the practical limitations of energy detection and compressive sensing are compared via simulation, and also implementation using the Universal Software Radio Peripheral (USRP) software defined radio (SDR) platform. The usefulness and simplicity of the USRP and GNU Radio software toolkit for simulation and experimentation, as well as some other application areas of compressive sensing and SDR, is also discussed

Use of frequency response masking technique in designing A/D converter for SDR.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.Analog-to-digital converters (ADCs) are required in almost all signal processing and communication systems. They are often the most critical components, since they tend to determine the overall system performance. Hence, it is important to determine their performance limitations and develop improved realizations. One of the most challenging tasks for realizing software defined radio (SDR) is to move ND conversion as close to the antenna as possible, this implies that the ADC has to sample the incoming signal with a very high sample rate (over 100 MSample/s) and with a very high resolution (14 -to -16 bits). To design and implement AID converters with such high performance, it is necessary to investigate new designing techniques. The focus in this work is on a particular type of potentially high-performance (high-resolution and highspeed) analog-to-digital conversion technique, utilizing filter banks, where two or more ADCs are used in the converter array in parallel together with asymmetric filter banks. The hybrid filter bank analog-todigital converter (HFB ADC) utilizes analog filters (analysis filters) to allocate a frequency band to each ADC in a converter array and digital synthesis filters to reconstruct the digitized signal. The HFB improves the speed and resolution of the conversion, in comparison to the standard time-interleaving technique by attenuating the effect of gain and phase mismatches between the ADCs. Many of the designs available in the literature are compromising between some metrics: design complexity, order of the filter bank (computation time) and the sharpness of the frequency response rolloff (the transition from the pass band to the stop band). In this dissertation, five different classes of near perfect magnitude reconstruction (NPMR) continuoustime hybrid filter banks (CT HFBs) are proposed. In each of the five cases, two filter banks are designed; analysis filter bank and synthesis filter bank. Since the systems are hybrid, continuous time IlR filter are used to implement the analysis filter bank and digital filters are used for the synthesis filter bank. To optimize the system, we used a new technique, known in the literature as frequency response masking (FRM), to design the synthesis filter bank. In this technique, the sharp roll-off characteristics can be achieved while keeping the complexity of the filter within practical range, this is done by splitting the filter into two filters in cascade; model filter with relaxed roll-off characteristics followed by a masking filter. One of the main factors controlling the overall complexity of the filter is the way of designing the model filter and that of designing the masking filter. The dissertation proposes three combinations: use of HR model filter and IlR masking filter, HR model filter/FIR masking filter and FIR model filter/FIR masking filter. To show the advantages of our designs, we considered the cases of designing the synthesis filter as one filter, either FIR or IlR. These two filters are used as base for comparison with our proposed designs (the use of masking response filter). The results showed the following: 1. Asymmetric hybrid filter banks alone are not sufficient for filters with sharp frequency response roll-off especially for HR/FIR class. 2. All classes that utilize FRM in their synthesis filter banks gave a good performance in general in comparison to conventional classes, such as the reduction of the order of filters 3. HR/HR FRM gave better performance than HR/FIR FRM. 4. Comparing HR/HR FRM using FIR masking filters and HR/IIR FRM using IIR masking filters, the latter gave better performance (the performance is generally measured in terms of reduced filter order). 5. All classes that use the FRM approach have a very low complexity, in terms of reduced filter order. Our target was to design a system with the following overall characteristics: pass band ripple of -0.01 dB, stop band minimum attenuation of - 40 dB and of response roll-off of 0.002. Our calculations showed that the order of the conventional IIR/FIR filter that achieves such characteristics is aboutN =2000. Using the FRM technique, the order N reduced to aboutN = 244, N = 179 for IIRJFIR and IIR/IIR classes, respectively. This shows that the technique is very effective in reducing the filter complexity. 6. The magnitude distortion and the aliasing noise are calculated for each design proposal and compared with the theoretical values. The comparisons show that all our proposals result in approximately perfect magnitude reconstruction (NPMR). In conclusion, our proposal of using frequency-response masking technique to design the synthesis filter bank can, to large extent, reduce the complexity of the system. The design of the system as a whole is simplified by designing the synthesis filter bank separately from the design of the analysis filter bank. In this case each bank is optimized separately. This implies that for SDR applications we are proposing the use of the continuous-time HFB ADC (CT HFB ADC) structure utilizing FRM for digital filters

A High-speed Reconfigurable Free Space Optical Communication System Utilizing Software Defined Radio Environment

Free space optical (FSO) communication allows for high-speed data transmissions while also being extremely cost-effective by using visible or infrared wavelengths to transmit and receive data wirelessly through the free space channel. However, FSO links are highly susceptible to the effects of the atmosphere, particularly turbulence, smoke, and fog. On the other hand, FSO itself does not provide enough flexibility to address the issue of such blockage and obstruction caused by objects and atmospheric conditions. This research investigates, proposes, and evaluates a software defined multiple input multiple output (MIMO) FSO system to ensure link availability and reliability under weather conditions as part of the last mile access in the 5th generation, 6th generation, and beyond. Software defined radio (SDR) technology is adopted in order to provide a certain degree of flexibility to the optical wireless communications system. The scope of this research focuses on the design, validation, implementation, and evaluation of a novel adaptive switching algorithm i.e., activating additional transmitters of a MIMO FSO system using a software defined ecosystem. The main issues are the compactness of the experimental design; the limitation of software-oriented signal generation; robustness; reliability; and the quality of service. As part of the system design, the thresholding method, a decision-making process via the feedback link, and a spatial diversity technique is adopted to carry out the adaptive switching. The adaptive switching is performed via a feedback link in which the atmospheric loss and scintillation index are calculated for fog and turbulence respectively. The initial design is implemented in SDR/ GNURadio for a real-time emulation of the proposed system to enhance the system flexibility of a traditional MIMO FSO system. A bit-by-bit comparison is performed with the GNURadio signal processing block and BERT for a real-time BER estimation. However, based on the initial results, the switching mechanism can only overcome the effect of turbulence at a certain level. A new design to mainly mitigate the varying fog conditions is proposed based on the SDR-based adaptive switching for a gigabit ethernet (GbE) MIMO FSO system and tested in a 5 m dedicated atmospheric chamber. The proposed system is implemented using off-the-shelf components such as a media converter, small form pluggable transceivers, optical switch, and power meter to estimate the channel state information. A new Schmitt trigger-based thresholding method is also introduced. The proposed software defined GbE MIMO FSO with an adaptive switching algorithm is fabricated, implemented, and investigated. The results are also compared with the real-time simulated data. Since the purpose of this Ph.D. is to explain and demonstrate the proof of concept for the proposed SDR-MIMO FSO system, the emphasis has been on the design, evaluation, and minimal performance requirements rather than maximizing the data rate. The outcome of the thesis will be a huge degree of flexibility and mitigation property MIMO FSO can offer with the help of SDR. It will be shown that the designed system has the capability to provide data transmission with 99.999% availability with a packet error rate and data rate of 7.2 ×10−2 and ~120 Mbps respectively, under extremely harsh fog conditions with visibility V of < 11 m

Software Defined Radio using MATLAB & Simulink and the RTL-SDR

The availability of the RTL-SDR for less than $20 brings SDR to the home and work desktops of EE students, professional engineers and the maker community. The RTL-SDR device can be used to acquire and sample RF (radio frequency) signals transmitted in the frequency range 25MHz to 1.75GHz, and using some official software add-ons, these samples can be brought into the MATLAB and Simulink environment for users to develop receivers using first principles DSP algorithms. Signals that the RTL-SDR hardware can receive include: FM radio, UHF band signals, ISM signals, GSM, 3G and LTE mobile radio, GPS and satellite signals, and any that the reader can (legally) transmit of course! In this free book we introduce readers to SDR methods by viewing and analysing downconverted RF signals in the time and frequency domains, and then provide extensive DSP enabled SDR design exercises which the reader can learn from. The hands-on examples begin with simple AM and FM receivers, and move on to the more challenging aspects of PHY layer DSP, where receive filter chains, real-time channelisers, and advanced concepts such as carrier synchronisers, digital PLL designs and QPSK timing and phase synchronisers are implemented. Towards the end of the book, we demonstrate how the RTL-SDR can be used with SDR transmitters to develop a more complete communications system, capable of transmitting text strings and images across the desktop

A conceptual framework for strategic long term planning of platinum mining operations in the South African context

The challenge facing a South African mining company, with multiple mining rights to platinum mineral resources, is to create sustainable value whilst operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to drive definition of the optimal (lowest capital and operating cost) technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near and longer term business environment shifts, i.e. a production mix that allows variation of output (metals, operating cost, capital intensity) to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the application of the strategic long term planning framework. The framework logic, methodology and components are described and the application demonstrated through a case study (Anglo Platinum Limited). Prior to definition and description of the strategic long term planning conceptual framework, the context of the South African platinum industry is described through consideration of the characteristics of the mineral resource, the platinum value chain, the PGM market, and the global and local business environment. The core elements of the framework, and the relationship between them, are expanded: scenario planning, business value optimisation, long term planning parameters, long term planning procedures, capital investment prioritisation, project value tracking, the relationship of the long term plan to the business plan, contingency planning and execution plans for supporting capability (projects, metallurgical, infrastructure and people). The implementation of the framework at Anglo Platinum Limited is considered over the period 2004 to 2007 with a description of the business response, facilitated by the framework and established capability, following the 2008 global financial crisis. It is concluded that the strategic long term planning framework is a logic construct that enables delivery of an optimised, strategically aligned, business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes that align decisions and actions on a cyclical basis

A knowledge management implementation framework for the Libyan banking sector

The principles of knowledge management (KM) are widely acknowledged and have been developed over the last 50 years, especially in such disciplines as management science, sociology, and construction. Whilst knowledge management (KM) is still an evolving practice, specific emphasis is now taking place on securing leverage through knowledge-context, interpretation, transfer, and reflection. Knowledge-based economies are increasingly reliant upon their intellectual capital (IC) cognisant of: the Information Technology (IT) revolution; expanding information society; the increased importance of knowledge; and the congruence and emergence of innovation through the application of KM practices. However, little work in the remit of KM has been evidenced in the Libyan financial sector the omission of which is the focus of this research. This research uses a case-study approach using an interpretive perspective to develop a knowledge management implementation (KMI) framework for the Libyan banking industry. The framework was developed and tested using three Libyan banks (LBs) and one bank from the United Kingdom (UK). Domain expertise was selected from the financial sector and academia to validate all results and findings. Research findings identified that the body of literature surrounding KM (from a Western perspective), could be applied to the Libyan context with a high degree of congruence. Moreover, the Libyan banking industry has now reached a level of maturity to embrace this framework as part of its core business practices. Several critical KM implementation areas were identified for incorporation (linked to organisational maturity). However, no definitive measurable leverage could be ascertained from this study, the aspect of which would need to form part of a larger study using cross-case analysis and multiple replications.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Governing sustainable corridor development:Case studies of Gilimanuk - Denpasar - Padangbai and Yogyakarta - Solo - Semarang Corridors

In 2015, the Government of Indonesia initiated the Strategic Development Regions Corridors, departing from the traditional corridor approach to a holistic perspective, as the corridors incorporate environmental preservation and socio-cultural considerations alongside economic interests. This poses challenges, since the traditional corridor approach often places environmental and socio-cultural concerns on passenger seats. Also, corridor projects claiming to be sustainable may not truly uphold their sustainability claims, without the balance between environmental, social, and economic dimensions. For this, the involvement of multiple stakeholders with sustainability knowledge and implementation capacities are needed. At the same time, actors have their perceptions, agendas, and strategies influencing the decision-making process that can either promote or hinder sustainability. This makes governance crucial for positioning actors with specific roles and responsibilities in the decision-making process to reach joint sustainability actions. This research delves into the governance of Gilimanuk-Denpasar-Padangbai and Yogyakarta-Solo-Semarang Corridors – exploring how it guides and directs actors’ behaviors. To do so, a conceptual framework was developed using regional development, corridor development, sustainable development, and governance theories to generate concepts of governance factors and interaction process that can steer a corridor development into sustainable direction. The findings revealed a shift from an initial economic focus to a broader consideration of sustainability. The corridors’ early sustainability vision, complemented by process management and process design allowed the inclusion and facilitation of sustainability actors with local, tacit, and codified knowledge. Nevertheless, limitations persisted due to the initial economic-focused top-down approach, resulting in economic-focused delineations and constrained soft-infrastructure programs in both corridors.<br/

A knowledge management implementation framework for the Libyan banking sector

The principles of knowledge management (KM) are widely acknowledged and have been developed over the last 50 years, especially in such disciplines as management science, sociology, and construction. Whilst knowledge management (KM) is still an evolving practice, specific emphasis is now taking place on securing leverage through knowledge-context, interpretation, transfer, and reflection. Knowledge-based economies are increasingly reliant upon their intellectual capital (IC) cognisant of: the Information Technology (IT) revolution; expanding information society; the increased importance of knowledge; and the congruence and emergence of innovation through the application of KM practices. However, little work in the remit of KM has been evidenced in the Libyan financial sector the omission of which is the focus of this research.This research uses a case-study approach using an interpretive perspective to develop a knowledge management implementation (KMI) framework for the Libyan banking industry. The framework was developed and tested using three Libyan banks (LBs) and one bank from the United Kingdom (UK). Domain expertise was selected from the financial sector and academia to validate all results and findings.Research findings identified that the body of literature surrounding KM (from a Western perspective), could be applied to the Libyan context with a high degree of congruence. Moreover, the Libyan banking industry has now reached a level of maturity to embrace this framework as part of its core business practices. Several critical KM implementation areas were identified for incorporation (linked to organisational maturity). However, no definitive measurable leverage could be ascertained from this study, the aspect of which would need to form part of a larger study using cross-case analysis and multiple replications